ML4824-1

The ML4824-1 is a controller for power factor corrected,switched mode power supplies. Power Factor Correction(PFC) allows the use of smaller, lower cost bulk capacitors,reduces power line loading and stress on the switchingFETs, and results in a power supply that fully complieswith IEC1000-2-3 specification. The ML4824-1 includescircuits for the implementation of a leading edge, averagecurrent, "boost" type power factor correction and a trailingedge, pulse width modulator (PWM).

The device is available in two versions; the ML4824-1(f_PWM = f_PFC) and the ML4824-2 (f_PWM = 2 x f_PFC).Doubling the switching frequency of the PWM allows theuser to design with smaller output components whilemaintaining the best operating frequency for the PFC. Anover-voltage comparator shuts down the PFC section in the event of a sudden decrease in load. The PFC section of ML4824-1 also includes peak current limiting and input voltage brown-outprotection. The PWM section can be operated incurrent or voltage mode at up to 250kHz and includes aduty cycle limit to prevent transformer saturation.